Yes, for example the Technic Axle Connectors used on the upper thighs do not exist in any shades of gold, but have been painted gold here.
The rules allow painted pieces, so that isn’t a barrier to qualification.
It’s worth pointing out that all the gold pieces on this build have been painted. It’s a shame the creator didn’t mention that in the description or when asked about painted pieces, because the shade of gold paint used isn’t pearl gold and can’t be reproduced with unmodified LEGO pieces.
I have a feeling purists wouldn’t be happy to know that all instances of the accent colour came out of a can, rather than being an official shade.